In recent years, three-dimensional (3D) display technology has undergone rapid development, particularly in the consumer market. High-resolution 3D glasses and visors are now possible. Using state-of-the-art microprojection technology to project stereoscopically related images to the right and left eyes, these display systems can immerse the wearer in a convincing virtual reality. Nevertheless, certain challenges remain for 3D display systems. One challenge is to position the virtual imagery accurately with regard to depth, despite moment-to-moment changes in the wearer's focal point.